Method and apparatus for catalytic conversion



Sept. i3, 1955 L. P. EVANS 2,717,353

METHOD ANO APPARATUS FOR OATALYTIO CONVERSION Filed April 9, 1951 j, l#aime vBY y ATTORNE United States Patent "O METHOD AND APPARATUS FORCATALYTIC CONVERSION Louis P. Evans, Woodbury, N. I., assigner to SoconyMobil Oil Company, Inc., a corporation of New York Application April 9,1951, Serial No. 220,010 Claims. (Cl. 196450) This invention pertains.to a process for conversion of hydrocarbons in the` presence of movinggranular contact material and particularly to processes in which theamount 'of carbonaceous contaminant deposited on the contact material islow relative to the amount of such deposits encountered in severecatalytic cracking and in which the conversion. activity of the contactmaterial is not seriously impaired by said deposits. Typical of theprocesses to which this invention may be applied are catalytichydrogenation, light cracking operations and reforming of hydrocarbonseither in the presence or in the absence of hydrogen.

This invention is directed 'to catalytic processes wherein the catalystis in granular form, the'term granular being employed to includepelleted, tableted, spherical pieces or pieces of regular or irregularshape. The average particle diameter should be broadly Within the vrangeabout 0.006 inch to 0.25 inch and preferably Within the range about 0.03inch to 0.18 inch.

Suitable catalysts may be selected from a Wide variety of materials.Among these are the oxides or sultides of the metals of the il, IV, V,Vl and VIH groups of the periodic system, especially chromium, tungsten,vanadium, molybdenum, cobalt and nickel deposited upon natural oractivated clays, magnesia, activated alumina, or synthetic gels ofsilica, alumina or silica and alumina.

in processes of the above-mentioned types `inwhich the deposition ofcarbonaceous contaminants on the catalyst is relatively low, thecatalyst need not be entirely regenerated since its eiiiciencyforhydrocarbon conversion remains at a practicable level until it hasaccumulated approximatelyI 5 per cent carbonaceous contaminant byweight.

Catalytic conversion `systems employingv moving granular beds ofcatalyst are generally of two types of construction. in the rst .theconversion vessel and regeneration vessel are placed side by side, aconveyor employed to transport catalyst from the bottom of the converterto the top of the regenerator and a second conveyor used to transportcatalyst from the bottom of the regenerator to the top of the converter.Separate surge zones are provided for converter and regenerator. In thesecond, converter and regenerator are placed one on top of the other anda single conveyor is supplied to transport catalyst to the uppermostvessel. Here again separate surge Zones are necessary for each vessel.This invention proposes a method whereby regenerator and converter areplaced side by side and a single conveyor and surge zone is provided toservice both vessels. This results in an economic advantage over both ofthe previously described systems. This saves the cost of one of theconveyors and a surge zone from the rst system and the cost of the addedunit height and a surge zone from the second system.

A major object of this invention is to provide a simple, compact,inexpensive method and apparatus for the vconversion of hydrocarbons inthe presence of moving granular contact material.

2,71 7,863 Patented Sept. 13, 1955 A; specific objectV of this inventionis to provide an improved method and apparatus for conductinghydrocarbon reforming ini the presence Cof a moving bedof granularcatalytic material.

Another object is the provision in such 'a process of a new and improvedmethod and apparatus foraccomplshing the catalyst circulation whichovercomesv the disadvantages of Vthe vprior art systems discussed-hereinabove. n;

These and other objects of this invention will become readily apparentfrom the following discussion.

According to one form of this invention converter and regenerator areplaced side by side. A surge vessel, containing a mixture vofregenerated and unregenerated used catalyst, is positioned above andbetween the converter and the regenerator. A portion of thiscatalystmixture gravitatescontinuously from the surge vesseliand passes throughthe regenerator wherein it contacts an oxygen containing gas whichburnsofi the 4carbonaceous deposits. The regenerated catalyst then passesthrough a gravity .feed leg and into a lift feed tankcommon to both theregenerator and the-converter. The remainder of the catalyst mixturegravitates continuously fromthe surgevessel and passes throughpressuring chambers and into the converter wherein it contacts ahydrocarbon feedto effect the desired conversion thereof. The catalystthen passesvthrough. a depressuring zone and` into the common liftfeed-tank. Here the used catalyst from the converter and the regeneratedcatalyst Vfrom! the Vregenerator are thoroughly mixed with a liftgas-and transported by means ofl this gas back to the surge vessel. Thesurge vessel also acts as a separator for the lift gas and catalyst.

This invention Will be more readily understood by reference to theattached drawing which is an elevational view, partially in section, ofa preferred arrangement of this invention. This drawing is` highlyVdiagrammatic in character. l

Referring` to the drawing, weiind converter' 10. and regenerator 11positioned side by side. The converter is provided with hydrocarbon feedconduit13 at its-center and product outlet conduits 14 and-15 at eitherend.V Also, the converter is equipped with a hydrogen inlet conduitl anda purge gas inlet V17. Vapor disengaging members (not shown) may beprovided at lthe top and bottom of vessel 10 in association with outlets14 and.15. Suitable disengaging arrangementsare shown in `Simpson etal., U. S. Patent 2,336,041, or Fahnestock, U. S. Patent 2,362,621. Thelower end of converter 10 may also be provided with battles adapted toeffectuniform with drawal of catalyst from all sections of` the,horizontal cross-sectional area of the conversion zone. VSuch battlesare shown in Evans et al., U. S. Patent 2,412,316. Regenerator 11 isprovided with inlet 18 for combustion supporting gas and outlets 19 and20 near its opposite ends. Heat transfer tubes not shown) with inlet 21and outlet 22 may also be provided within the regenerator to controlregeneration temperature. A combination surge vessel and catalystseparator 23 is positionedv above and between converter 10 andregenerator -11. A cylindrical bame 24 depends downwardly from the topof chamber 23 so as to leave an annular space 25 between :the baille andthe wall of cylinder 23. A catalyst lift `pipe 26 terminates just belowbaille 24 and a gas outlet conduit 27 communicates with annular space2'5.v Two-catalyst drain conduits 28 and'29 are provided at the bottomof chamber 23.

Conduit 28 connects into the top of regenerator `11. Conduit 29 connectsinto the top of converter 10 and has spaced valong its length`depressuring chambers 30 and 31. vMotor operated valves 3S, 36 and 37are placed above chamber 30, Abetweencha'mbers 30 and 31, and

below chamber 31 respectively. These valves are operated by controller38. Chamber is equipped with a conduit 44 having a motor controlleddiaphragm valve for the introduction of an inert gas such as steam orilue gas into chamber 30. Chamber 30 is also provided with an inert gasoutlet conduit 68 having a motor controlled diaphragm valve 41. Valves40 and 41 are operated by controller 39. Chamber 31 has a conduit 45 forinert gas ow equipped with a diaphragm valve 43 which is operated by adifferential pressure controller 42. Converter 10 has a catalyst outlet69 which connects to three depressuring chambers 46, 47 and 48 inseries. These chambers are adapted to effect the release of gaseouspressure without break in the catalyst stream and without loss ofcatalyst. The pressures within chambers 46, 47 and 48 are controlled bymeans of diaphragm valves 49, and 51 respectively. Suitable depressuringchamber constructions are described in United States Patent 2,448,272issued August 31, 1948. If desired, one,

two or more than three depressuring chambers may be used. Conduit 52extends downwardly from the bottom of depressuring chamber 48 to liftfeed tank 57. A catalyst outlet conduit 58 is provided at the bottom ofregenerator 11. Conduit 58 terminates in a vented hopper 59 which ispositioned at the upper end of a gravity leg 60. This leg should bevertical over most of its length and of sufficient height to overcomethe pressure differential between hopper 59 and lift feed tank 57. Itshould preferably be of tapered construction its diameter decreasing atsuccessively lower levels. Suitable tapered gravity legs are describedin United States patent application, Serial Number 329,882, filed June6, 1953. Lift feed tank 57 is situated below and between converter 10and regenerator 11. Vertical lift feed pipe 26 having a ared lower endextends upwardly from within feed tank 57 into separator 23. At the topof feed tank 57 are provided catalyst inlet passages 53 and 56 which areformed by vertical pipe sections 54 and 55 of differing diameters.Sections 54 and 55 are arranged concentrically with respect to lift pipe26 and extend a short distance above and below the top of feed tank 57.The pipe of larger diameter is connected to the top of the lift feedtank and a closure 70 is provided over the upper ends of both pipes.Conduit 52 extends into section 53 while gravity leg 60 extends intosection 56. A gas distributor manifold 61 having a perforated upper endextends upwardly from the bottom of feed tank 57 to a point directlybelow the ared lower end of lift pipe 26 so as to form anular passage62. A gas inlet conduit 63 having a flow control valve 64 thereonconnects into the bottom of tank 57 below manifold 61. A ring shapedangle member 67 is attached to the inner periphery of feed tank 57 andserves as a gas distributor for a second stream of gas which is providedby conduit 65 with control valve 66 thereon.

In operation separator 23 serves both to separate lift gas and catalystparticles and to provide a surge or supply vessel for the separatedparticles. The separating function of 23 is performed in the uppersection while surge or supply space is provided in the lower. Mixed usedand regenerated catalyst ows from this surge space through conduit 29and is admitted upon the opening of valve 35 to chamber 30. Valve 35then closes and gaseous pressure is built up in chamber 30 by means ofinert gas supplied through conduit 44 and valve 40 to a point slightlyabove the gaseous pressure in chamber 31. Valve 36 then opens andcatalyst flows from charnber 30 to chamber 31. Valve 36 closes andchamber 30 is depressured by releasing the gas therein through conduit68 and valve 41. The pressure in chamber 31 is maintained slightly abovethat in converter 10 by means of inert gas introduced through conduit45. After valve 36 has closed valve 37 then opens and catalyst flowsinto converter 10. Controller 38 operates valves 35, 36 and 38 so thatvalves 35 and 37 open together a fixed time after valve 36 closes thisxed time being the time necessary to depressure chamber 30 throughconduit 68. Valve 36 then opens a xed time after valves 35 and 37 closethis fixed time being the time necessary to pressure chamber 30 withinert gas through conduit 44. Controller 39 operates valves 40 and 41 ona time cycle in conjunction with that of controller 38. Catalystgravitates through the conversion zone within converter 10 as a compactmoving bed and is contacted therein by a naphtha feed which entersthrough conduit 13. A hydrogen containing gas may be admitted to theconversion Zone through conduit 16. Gaseous conversion products arewithdrawn from the converter through conduits 14 and 15. Used catalystfrom the conversion zone is purged free of gaseous hydrocarbon productsin the lower section of converter 10 by means of an inert purge gas,such as steam or flue gas, admitted through conduit 17. The purged usedcatalyst is removed from converter 10 through conduit 69 and passesthrough depressuring charnbers 46, 47 and 48 wherein the gaseouspressure is successively reduced by means of diaphragm valves 49, 50 and51. The gaseous pressure in chamber 48 is maintained slightly above thatin lift feed tank 57. Used catalyst flows through conduit 52 intoannular passage 53 at the top of lift feed tank 57.

A second stream of mixed used and regenerated catalyst ows from thesurge section of separator 23 through 28 into the upper end ofregenerator 11. Catalyst llows through the regeneration zone withinregenerator 11 as a compact column and is contacted therein by acombustion supporting gas, such as air, admitted through conduit 18.Flue gas is removed by means of conduits 19 and 20. Catalyst passesthrough the regenerator and is removed through conduit 58. Thisregenerated catalyst passes into vented hopper 59 from which it owsthrough gravity leg 60 into annular passage 56 in lift feed tank 57.Used and regenerated catalyst from passages 53 and 56 are mixed to acertain degree as they flow with the main body of the catalyst withinlift feed tank 57. Lift gas admitted through conduit at a ratecontrolled by valve 66 forces catalyst particles up into annular passage62 Where said particles are contacted by a second stream of lift gasflowing through perforations in the top of manifold 61. Catalystparticles are suspended in the lift gas and transported upwardly throughlift pipe 26 into separator 23. Particles of used and regeneratedcatalyst are thoroughly mixed by the lift gas during passage throughpipe 26 so that a uniformly mixed catalyst ows into separator 23. Liftgas is removed from separator 23 through conduit 27 and the mixedcatalyst falls downwardly onto the surge bed in the lower section ofseparator 23.

The lift feed tank in the process described above is operated at apressure slightly above atmospheric pressure. However in some operationsit may be desirable to develop a pressure differential across lift pipe26 by evacuating the separator while maintaining the lift [ccd tank atatmospheric pressure. For example it steam is used as the lift gas abarometric condenser could be attached to' conduit 27 to maintain avacuum within separator 23. Such a system is described in U. S. patentapplication, Serial Number 75,642, tiled February l0, 1949, now U. S.Patent No. 2,684,927. Also, while operation of the separator atatmospheric pressure is generally desirable, it is contemplated withinthe broader scope of this invention that the separator may bc operatedat a pressure above as well as below atmospheric pressure. It is furthercontemplated within the broader scope of this invention that naldepressuring of the catalyst stream after passage through the convertermay be to atmospheric pressure with a gravity feed leg provided belowthe lower depressuring chamber to feed catalyst to lift feed tank. ltshould also be understood that the hydrocarbon feed may be introduced atthe top or bottom of the converter rather than the center as describedherein and that'the introduction ofhydrogen containing gas'into thereactoris not essential-tothe broader forms of this invent-ion.

It should be notedl that in this invention the -used and regeneratedcatalystv are thoroughly mixedbe'fore being contacted by either theregeneration gas orlthe hydrocarbon feed. This is Vanimportant part-ofthe operation since contact `of a non-uniform mixture of used andregenerated catalyst by the regeneration gas might result in thetemperature of lthe catalyst at certain points becoming so high as topermanently injure the catalyst while contact of a non-uniform mixtureby the hydrocarbon feed might result in `over-conversion of a portion ofthe feed andunder-conversion of the remaining portion. Thisinventionhasthe further advantage that a separate mixing step is `notrequired to achieve this uniform mixture since the catalyst isthoroughly mixed while being transported lbythe gas lift tolthe supplyhopper.

Broadly, the converter in this invention when used for reforming shouldbe operated at pressureswithin'the range about 25 to l000pounds Vpersquare inch and preferably within the range 'about 15 to 400 pounds persquare inch and temperatures within the range about 800 F. to 1100 F.and preferablyabout900y F: to 1050 F. This `invention is 'noti limitedin its broadest form to any particular range of gas velocities orcatalyst stream densities in the lift `pipes but it is preferable thatthe linear upward gas velocity be within the range about 80 to 130 feetper second` and`that the stream density be within the range about 1 to30 pounds Vper cubic foot on the basis of a `catalyst having acompactflowing density of about 45 pounds per cubic foot and a particlesize of about 4 to v16 mesh Tyler. The effect of the percentage ofcarbonaceous contaminants onthe 'catalyst depends on the converterand'conversion conditions 1n volved. ln reforming operations the mixedused and regenerated catalyst which-is fed lto the converter andregenerator should have an average'carbonaceous contaminant deposit notexceeding yabout 2 per cent by weight. `Also the deposits on the usedcatalyst being recycled should 'not 'exceed about 6V per centby weightand preferably should *netbe* greater than about- 4 per cent by weight.The conditions of temperature,tpres sure, space velocity, residence timeand hydrocarbon concentration within the converter shouldlbe controlledto limit the amount of deposits on the used catalyst below the abovelimits. Conditions outside these-ranges may be used when conversionsyother than reforming are practiced within the scope Vof this invention.

As typical of the operation according to this invention, its applicationto the reforming of a petroleum naphtha charging stock containingmostlyparafiinic and naphthenic hydrocarbons may be considered. Thegranular catalyst maycomprise particles of alumina with chro mium oxidedepositedthereon and may be of the order of 4 to 20 mesh size by' Tylerstandardfscreen analysis. Converter maybe maintained'a't a pressure of,for example, pounds per square inch gauge. Pressuring chambers and 31would `thenV operateat 26and 251/2 pounds per square inch gauge,respectively. The naphtha feed having, for example, a l0 per centA. S.T. M. boiling point at 300 F. and an end point'of 425 F. is introducedinto the converter at a temperature of 950 F. Hydrogen is also suppliedto theconve'rter in the ratio of about 5 mols` of hydrogen to one mol ofhydrocarbon charge. Depressuring chambers 46, 47 and 48 may bemaintained at 15," 7 and 2'poundsper square inch gauge, respectively.IRegenerator 11 may be operated at a pressure slightly above atmosphericpressure for example 2 pounds 4per square inchfgauge. The temperature ofthe catalyst thereinf is best controlled below 1100 F. to avoidpermanent damage -to the catalyst by overheating. vLift feed-tank 57 may-also be ari-7,863

6 maintainedv at a'pressure slightly above atmospheric for example 2 to4 lpounds per square inch gauge.

This invention should be understood to cove'r all changes andmodifications of the examples ofthe invention herein chosen for thepurposes of disclosure which do not constitute departures from thespirit and scope of this invention.

I claim:

1. In a process for the conversion of hydrocarbons by a moving granularcatalyst wherein at least two separate zones are maintained the first ofwhich is a conversion zone in which hydrocarbon feed is contacted by amoving `bed of granular catalyst to effect the conversion -of saidhydrocarbon feed and thereby deposit carbonaceous contaminant on thecatalyst in an amount less than the amount of carbonaceous contaminantwhich reduces Vthe efliciency of the hydrocarbon conversion belowl apractical =low level, the second of which is a regeneration zone inwhich carbonaceous contaminant is removed'from the catalyst bycontacting said catalyst with a combustion supporting gas to effectremoval of said contaminant by burning the improvement which comprises,passing at least a portion of used catalyst from the conversion zone toa location where it issuspended in a suitable carrying gas, passing atleast a portion of the regenerated catalyst from the regeneration zoneto said location where it is also suspended in said carrying gas,passing the resulting stream of used and regenerated catalyst suspendedin said carrying gas upwardly through a confined passage to a locationfrom which at least a portion of said catalyst may flow to saidconversion zone whereby a uniformly mixed stream of used and regeneratedcatalyst is supplied to said bed within said conversion zone.

2. In a process for the conversion of hydrocarbons by a moving granularcatalyst lwherein hydrocarbon feed is Vpassed into a conversion zone andinto contact with a moving bed of granular catalyst therein atsuitabletemperature and pressure for effecting the conversion of the hydrocarbonfeed and wherein a regeneration zone is maintained in which carbonaceouscontaminant deposited on lthe catalyst during the conversion is burnedfrom the catalyst by contacting said catalyst with a combustionsupporting gas, the conversion reaction of the process remaining at apractical level in spite of deposits of carbonaceous contaminant up todeposits of about five per cent by weight of catalyst and the reactiondepositing an amount of carbonaceous contaminant on the catalystsubstantially less than fve per cent by weight of the catalyst, theimprovement which comprises, passing at least a portion of the usedcatalyst from the conversion zone to a location where it is suspended ina suitable carrying gas, passing the regenerated catalyst from theregeneration zone to said location where it is also suspended in thecarrying gas, passing the resultant stream of used and regeneratedcatalyst suspended in said carrying gas upwardly through a confinedpassage to a confined separation zone located above said conversion zonewhereby the used and regenerated catalyst granules are simultaneouslylifted and thoroughly mixed, effecting separation of the carrying gasfrom the mixed catalyst in said separation zone and withdrawing Vthecarrying gas therefrom and flowing at least a` portion of the mixedcatalyst downwardly to the conversion zone to replenish the catalyst bedtherein.

3. In a process for the conversion of hydrocarbons in the presence of amoving compact bed of granular catalyst wherein the conversion reactionremains at a practicable level even though carbonaceous contaminants aredeposited on the catalyst up to an average deposit amounting to aboutfive per cent by weight of the catalyst, the improved mode of operationwhich comprises: passing a hydrocarbon feed into a confined conversionzone wherein 'the hydrocarbon feed contacts a substan tially compact bedof moving granular catalyst at conversion temperature and pressure toeffect the desired conversion to gasiform products, withdrawing thegasiform products from the conversion Zone, passing used catalystbearing a carbonaceous contaminant deposited during the conversion to amixing zone where it is mixed with a suspending gas, passing the usedcatalyst suspended in said gas upwardly through a confined lift passageto a separation zone maintained at a higher level than said conversionzone, effecting separation of the lift gas from the catalyst in saidseparation zone and withdrawing the lift gas therefrom, collecting theseparated catalyst on a surge bed thereof, Ypassing a portion of thecatalyst from the surge bed downwardly to and through a confinedregeneration zone wherein it is contacted with a combustion supportinggas to burn off said carbonaceous contaminant, passing regeneratedcatalyst from the regeneration zone to said mixing Zone to become mixedwith said used catalyst and said suspending gas, passing saidregenerated catalyst suspended in said gas upwardly through said liftpassage along with said used catalyst and also collecting saidregenerated catalyst mixed together with said used catalyst on saidsurge bed and passing a second portion of said catalyst from said surgebed downwardly into said conversion Zone to supply the bed of catalysttherein.

4. In a process for the conversion of hydrocarbons in the presence of amoving compact bed of granular catalyst wherein the conversion reactionremains at a practicable level even though carbonaceous contaminants aredeposited on the catalyst up to an average deposit amounting to abouttive per cent by weight of catalyst and wherein the conversion reactiondeposits an amount of carbonaceous contaminant substantially less thanabout five per cent by weight of the catalyst, the improved mode ofoperation which comprises: maintaining a supply bed of uniformly mixedregenerated and used catalyst, passing a portion of said mixed catalystdownwardly from said bed to a confined conversion Zone and passing itdownwardly through at least a portion of said zone as a substantiallycompact bed of gravitating material, passing a hydrocarbon feed intocontact with said bed to contact said catalyst under conversionconditions of temperature and pressure, whereby it is converted togasiform hydrocarbon products while a carbonaceous contaminant isdeposited on the catalyst, withdrawing said gasiform product from saidconversion zone, passing a second portion of said mixed catalyst fromsaid supply bed downwardly to and through a conned regeneration Zonewhile contacting it in said regeneration zone with a combustionsupporting gas to burn off the contaminant, passing regenerated catalystdownwardly to a location where it is mixed with a lift gas to effect itssuspension therein, passing used catalyst from Said conversion zonedownwardly to said location to mix with the lift gas and saidregenerated catalyst, passing the used and regenerated catalyst insuspension in said lift gas upwardly through a confined lift passage toa separation zone located above said Supply bed, effecting separation ofsaid lift gas from said catalyst in said separation zone and collectingthe separated thoroughly mixed catalyst on said supply bed to replenishthe same.

5, ln a cyclic process for reforming of hydrocarbon fractions to producehigh octane gasoline in the presence of a moving compact bed of granularcataiyst wherein the conversion reaction remains at a practicable leveleven though carbonaceous contaminants are deposited on the catalyst upto an average deposit amounting to about live per cent by weight ofcatalyst which comprises, maintaining a substantially compact bed of asuitable dehydrogenation catalyst in a confined reforming zone,maintaining a bed of mixed used and regenerated dehydrogenation catalystin a supply zone located at a level above said reforming zone, owing astream of the mixed catalyst from said supply zone downwardly into saidreforming zone to maintain said bed therein replenished, passing ahydrocarbon naphtha fraction into contact with said catalyst in thepresence of an added hydrogen containing gas to effect reforming of saidnaphtha to form a product containing high octane gasoline while acarbonaceous contaminant is deposited on the catalyst, withdrawing saidgasoline containing product from said reforming Zone, passing a secondstream of the mixed catalyst downwardly from said supply zone to andthrough a regeneration zone while contacting the catalyst in saidregeneration zone with a combustion supporting gas to effect removal ofcarbonaceous contaminant from said catalyst by burning, passingregenerated catalyst from said regeneration zone and used catalyst fromsaid reforming zone downwardly to a mixing zone and contacting thecatalyst in said mixing zone with a lift gas to effect its suspensiontherein, passing the used and regenerated catalyst suspended in saidlift gas upwardly as a confined lift stream, whereby the used andregenerated catalyst granules are simultaneously elevated and thoroughlymixed, discharging the mixed catalyst upwardly from said lift streaminto an expanded separation zone, effecting separation of said catalystfrom said lift gas in said separation zone and gravitating the separatedmixed catalyst downwardly onto said supply bed.

6. In a cyclic process for reforming of hydrocarbon fractions to producehigh octane gasoline in the presence of a moving compact bed of granularcatalyst wherein the conversion reaction remains at a practicable leveleven though carbonaceous contaminants are deposited on the catalyst upto an average deposit amounting to about tive per cent by weight ofcatalyst which comprises, maintaining a substantially compact bed of asuitable dehydrogenation catalyst in a confined reforming zone, passinga hydrocarbon fraction boiling within the range in which naphtha andmotor gasoline boil into contact with said catalyst in the presence ofan added hydrogen containing gas to effect reforming of said naphtha toform a product containing high octane gasoline while a carbonaceouscontaminant is deposited on the catalyst, withdrawing said gasolinecontaining product from said reforming zone, maintaining a bed ofdehydrogenation catalyst comprising a mixture of catalyst which has beenused for the conversion in said reforming zone and catalyst which hasbeen regenerated in the lower portion of a confined settling Zonemaintained at a level above said reforming Zone, the used catalyst insaid mixture bearing a carbonaceous contaminant deposit less than about6 per cent by weight of the used catalyst, passing a first stream ofsaid mixed catalyst downwardly from said settling zone to said reformingZone to supply the bed of catalyst therein, passing a second stream ofthe mixed catalyst downwardly from said supply zone to and through aregeneration zone while contacting the catalyst in said regenerationzone with a combustion supporting gas to effect removal of carbonaceouscontaminant from said catalyst by burning, passing regenerated catalystfrom said regeneration zone and used catalyst from said reforming zonedown- ,i wardly onto a bed of said catalyst in a lift feed Zone,

passing used and regenerated catalyst together upwardly through aconfined passage in suspension in a lift gas from a location within saidbed in said lift feed zone to a location above said bed in said settlingzone, whereby the used and regenerated catalyst are simultaneouslyelevated and mixed, permitting the stream from said lift passage toexpand in said settling zone, whereby the catalyst settles from the liftgas, collecting the settled mixed catalyst on said bed in said settlingzone and withdrawing lift gas from an upper section of said lift zone.

7. In a cyclic process for reforming hydrocarbons in the presence of amoving compact bed of granular catalyst wherein the conversion reactionremains at a practicable level even though carbonaceous contaminants aredeposited on the catalyst up to an average deposit amounting to about veper cent by weight of catalyst which comprises, maintaining a surge bedof uniformly mixed used and regenerated dehydrogenation catalyst, theused catalyst in said mixture bearing a carbonaceous contaminant depositless than about 4 per cent by weight of the used catalyst and theaverage carbonaceous contaminant deposit of the catalyst mixture beingless 2 per cent by weight, passing a stream of said dehydro genationcatalyst from the surge bed into a reforming zone, contacting thecatalyst within the reforming zone with a hydrocarbon naphtha feed toelect conversion of the hydrocarbon feed to a gasiform productcontaining high octane gasoline while depositing carbonaceouscontaminant on the catalyst, withdrawing said gasiform product from thereforming zone, passing a second stream of said mixed catalyst from thesurge zone downwardly to and through a coniined regeneration zone whilecontacting it in said regeneration zone with a combustion supporting gasto effect the removal of said carbonaceous contaminant by burning,passing the regenerated catalyst downwardly to a mixing zone wherein itis mixed with a lift gas to effect its suspension therein, passing usedcatalyst from the reforming zone downwardly to said mixing zone andmixing the used catalyst therein with the lift gas and said regeneratedcatalyst, passing the used and regenerated catalyst suspended in thelift gas upwardly through a conned lift passage to a separation zonelocated above said surge bed, separating the unil formly mixed catalystfrom the lift gas in said separation zone, effecting the removal of saidlift gas from said separating zone, and collecting the separatedthoroughly mixed catalyst on said surge bed to replenish same.

8. A cyclic system for reforming petroleum naphtha which comprises, incombination: a conversion vessel adapted to conne a compact bed ofgranular catalyst, means to supply reactant to said vessel and means towithdraw reactant from said vessel, a catalyst inlet connected into theupper end of said vessel and a catalyst outlet connected into the lowerend thereof, a separate regenerator vessel having a catalyst inlet atits upper end and a catalyst outlet at its lower end, said regenerationvessel being positioned alongside of said conversion vessel, a lift feedtank below said conversion and regeneration Vessels and a settlingchamber positioned above said conversion and regeneration vessels, a gasoutlet connected into the upper section of said settling chamber,passage defining means for catalyst iow from the lower section of saidsettling chamber to said catalyst inlet on said conversion vessel,passage defining means for catalyst ow from the lower section of saidsettling chamber to said catalyst inlet on said regeneration vessel, asubstantially vertical lift conduit extending upwardly from a locationwithin said lift feed tank intermediate its upper and lower ends to alocation within said settling chamber intermediate its upper and lowerends, means to supply a lift gas to said litt feed tank, passage deningmeans for a catalyst flow from the catalyst outlet on said conversionvessel to said lift feed tank, and passage defining means for catalystflow from said catalyst outlet on said regeneration vessel to said liftfeed tank, whereby catalyst from said conversion vessel and saidregeneration vessel are mixed by the lift gas in the lift feed tank andtransported upwardly through the lift pipe to the settling chamber.

9. A cyclic system for reforming petroleum naphtha which comprises incombination, an elongated conversion vessel having reactant inlet andoutlet means, a separate 10 elongated regeneration vessel having gasinlet and outlet means, a lift feed tank located below said reactor andregeneration vessel, means for cooling said regeneration vessel, a liftfeed tank positioned below and between said conversion and regenerationvessels, a catalyst separator positioned above and between saidconversion and regeneration vessels said separator, a substantiallyvertical tending from a point within said lift feed tank between theupper and lower ends of said lift feed tank into said separator to apoint between its upper and lower ends, a passage defining means fromthe lower section of said separator to said catalyst inlet on saidconversion vessel separator.

References Cited in the lile of this patent UNITED STATES PATENTS

1. IN A PROCESS FOR THE CONVERSION OF HYDROCARBONS BY A MOVING GRANULARCATALYST WHEREIN AT LEAST TWO SEPARATE ZONES ARE MAINTAINED THE FIRST OFWHICH IS A CONVERSION ZONE IN WHICH HYDROCARBON FEED IS CONTACTED BY AMOVING BED OF GRANULAR CATALYST TO EFFECT THE CONVERSION OF SAIDHYDROCARBON FEED AND THEREBY DEPOSIT CARBONACEOUS CONTAMINANT ON THECATALYST IN AN AMOUNT LESS THAN THE AMOUNT OF CARBONACEOUS CONTAMINANTWHICH REDUCES THE EFFICIENCY OF THE HYDROCARBON CONVERSION BELOW APRACTICAL LOW LEVEL, THE SECOND OF WHICH IS A REGENERATION ZONE IN WHICHCARBONACEOUS CONTAMINANT IS REMOVED FROM THE CATALYST BY CONTACTING SAIDCATALYST WITH A COMBUSTION SUPPORTING GAS TO EFFECT REMOVAL OF SAIDCONTAMINANT BY BURNING THE IMPROVEMENT WHICH COMPRISES, PASSING AT LEASTA PORTION OF USED CATALYST FROM THE CONVERSION ZONE TO A LOCATION WHEREIT IS SUSPENDED IN A SUITABLE CARRYING GAS, PASSING AT LEAST A PORTIONOF THE REGENERATED CATALYST FROM THE REGENERATION ZONE TO SAID LOCATIONWHERE IT IS ALSO SUSPENDED IN SAID CARRYING GAS, PASSING THE RESULTINGSTREAM OF USED AND REGENERATED CATALYST SUSPENDED IN SAID CARRYING GASUPWARDLY THROUGH A CONFINED PASSAGE TO A LOCATION FROM WHICH AT LEAST APORTION OF SAID CATALYST MAY FLOW TO SAID CONVERSION ZONE WHEREBY AUNIFORMLY MIXED STREAM OF USED AND REGENERATED CATALYST IS SUPPLIED TOSAID BED WITHIN SAID CONVERSION ZONE.